JP3778796B2 - Color image transfer method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a color image transfer method using a sublimable dye.
[0002]
[Prior art]
Conventionally, when a color image printed on transfer paper with sublimation dye ink is transferred to a transfer object, the transfer paper is placed on the transfer object and pressed under heat to transfer the color image to the transfer object. FIG. 2 illustrates a conventional general transfer method. Here, various materials such as nameplates, panels, stickers, display boards for instrumentation, exterior parts for electronic devices such as game machines and portable devices, and decorative containers for daily goods can be transferred. You can choose one. When these transfer objects are described by taking, for example, a metal display board as an example, a structure as shown in FIG. 3 is known.
[0003]
FIG. 3 shows a display panel on which a color image is formed with a sublimable dye. In the illustrated display board 100, a transparent receiving layer 102 is formed on the upper surface of a metal substrate 101, and a color image 103 for display is formed in the receiving layer 102 by a transfer method. Various metal plates such as aluminum, brass, and iron can be selected for the metal substrate 101, and these are subjected to surface treatment such as plating or painting for the purpose of rust prevention or decoration. The receiving layer 102 is provided for the purpose of forming an image therein, and is formed by a printing or coating method using a resin such as polyurethane resin, polyester resin, epoxy resin, or acrylic resin. Then, a color image 103 with a sublimation dye is formed in the receiving layer 102 by a transfer method described later. In addition, an ultraviolet absorber is dispersed in the receiving layer 102. Since sublimation dyes are not very light resistant to ultraviolet light, the light resistance is enhanced by dispersing an ultraviolet absorber.
[0004]
The method of transferring and forming the color image 103 in the receiving layer 102 is performed by the method shown in FIG. That is, a transfer paper 112 on which a metal substrate 101 on which a receiving layer 102 is formed is placed on a smooth finished article 111, and a color image is formed thereon by an ink jet printer using sublimation dye ink. Then, the transfer paper 112 is pressed by the pressing tool 113 which is finished smoothly under heating. In this way, the sublimation dye that forms the color image of the transfer paper is vaporized by heating, and the vaporized dye penetrates into the softened receiving layer 102 under pressure, and enters the receiving layer 102. A color image 103 with the vaporized sublimation dye is formed.
[0005]
Here, the heating temperature varies depending on the type of resin forming the receiving layer 102. For example, when a polyurethane resin is used, the heating is performed at a temperature of about 180 ° C. Generally, it is better to heat around the softening point temperature of the resin used. The applied pressure may be about 10 g / cm ² , and when pressed for about 1 to 3 minutes, the dye penetrates to a considerably deep portion of the receiving layer 102 to form a beautiful color image 103.
[0006]
It is also important to penetrate the sublimation dye as deeply as possible in the receiving layer 102. In that sense, the thickness of the receiving layer 102 needs to be at least 10 μm or more. If it is thinner than this, the permeated dye will be easily removed, and a beautiful color image cannot be maintained forever. The thickness of the receiving layer 102 is generally preferably in the range of 20 to 50 μm. Further, the pressing force and pressurizing time also affect the penetration depth. Since the pressing force and the pressurizing time are related to each other, it is preferable to set an optimum place as appropriate.
[0007]
A color image formed using sublimation dye ink on transfer paper is printed by an ink jet printer. This color image can be selected from a variety of color images such as photographic images, paintings, other pattern images, and color images consisting of the entire surface. When a color image is printed using a sublimable dye ink of magenta, yellow, cyan, and black, and a 1440 dpi printer is used for printing, a very beautiful color image can be formed.
[0008]
The conventional technology described above is a case where a metal plate is used. However, in the case of a molded article using a plastic material, a color image is directly transferred to the surface portion of the plastic material by a similar method. A molded product is obtained.
[0009]
[Problems to be solved by the invention]
Transferring by the above method to form a color image on the receiving layer has conventionally had the following problems. As a first problem, since pressure is applied to the transfer, the fine uneven paper pattern of the transfer paper is also transferred to the receiving layer, and the appearance of the receiving layer is impaired. For this reason, conventionally, it has been necessary to perform surface polishing again after transfer, which has been a factor of increasing costs.
[0010]
As a second problem, although the receiving layer is formed by a printing method or the like, gentle unevenness or the like is generated on the surface, and a thin portion and a thick portion appear in the thickness of the receiving layer, and the pressing force is not applied constantly. Image unevenness occurs between a thin portion and a dark portion in the transferred image.
[0011]
As a third problem, since the color image of the transfer paper is formed by an ink jet printer, the image is composed of a collection of minute dot-like spots. When the dot-like spots are not sufficiently mixed with the sublimable dye after the transfer, they may appear as dot-like marks on the receiving layer. In such a case, the appearance of the color image is greatly impaired. Conventionally, in order to erase the dot-like traces, a heat treatment is performed at a temperature of 200 to 270 ° C. for 5 to 15 minutes under no pressure so that the mixing of the dyes is promoted to erase the dot-like traces. I have to. For this reason, the number of processes has increased, which has been a factor in increasing costs.
[0012]
[Means for Solving the Problems]
The present invention has been made in view of the above problems, and the object of the present invention is to provide a transfer method for obtaining a beautiful color image in which the pattern marks on the transfer paper are not transferred and the dot-like marks on the dye are not generated. To find. In order to achieve this object, the invention according to claim 1 of the present invention provides a method for transferring a color image of transfer paper formed with a sublimation dye ink to a transfer object under heating and pressurization. A transparent film sheet is sandwiched between paper and a receiving layer formed on the transfer object, and transferred.
[0013]
The invention according to claim 2 of the present invention is characterized in that the transparent film sheet has a thickness of 25 to 50 μm.
[0014]
In the invention according to claim 3 of the present invention, the transparent film sheet is made of one or more resins selected from polypropylene resin, polyethylene resin, polycarbonate resin, nitrocellulose resin, nitrofuron resin and acrylic resin. It is a formed film sheet.
[0015]
The invention according to claim 4 of the present invention is characterized in that the surface of the receiving layer is polished to be a smooth surface.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
The embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory view showing a transfer method according to an embodiment of the present invention. Since the transfer apparatus used is the same as that of the conventional method, the same reference numerals are used for explanation. In addition, a display plate is used as an object to be transferred as in the conventional case.
[0017]
In FIG. 1, the display board 10 is placed on the product tool 111. This display board 10 is obtained by forming a receiving layer 12 on the upper surface of a metal substrate 11. The metal substrate 11 can be selected from various metal plates such as aluminum, brass and iron, and is subjected to surface treatment such as plating or painting for the purpose of rust prevention or decoration. The receiving layer 12 is formed by printing or painting using a paint in which an ultraviolet absorber is dispersed in polyurethane resin, polyester resin, epoxy resin, acrylic resin, or the like. Furthermore, the upper surface 12a of the receiving layer 12 is finished to a glossy and smooth surface by polishing.
[0018]
Reference numeral 112 denotes a transfer paper, which is the same as that described in the prior art. A transparent film sheet 15 is sandwiched between the display board 10 and the transfer paper 112. The film sheet 15 is made of a resin such as a polypropylene resin, a polyethylene resin, a polycarbonate resin, a nitrocellulose resin, a nitrofuron resin, or an acrylic resin, and has a glossy and smooth surface. The resin forming the film sheet 15 is not limited to the above resin, and any other resin can be selected as long as it has a relatively high heat resistance. A water-repellent resin such as a fluorine resin is not preferable. The transparent film sheet 15 is selected to have a thickness in the range of 25 to 50 μm.
[0019]
Next, after the film sheet 15 and the transfer paper 112 are overlaid on the display board 10, transfer is performed by applying pressure with the pressing tool 113 under heating. The heating temperature and the applied pressure may be the same as in the conventional method, but it is better to apply the pressurization time slightly longer. For example, what is conventionally performed in 90 seconds may be set a little longer to about 100 to 110 seconds.
[0020]
By adopting such a transfer method, the sublimation dye forming the color image of the transfer paper penetrates into the film sheet 15 and further penetrates into the receiving layer 12 so that a beautiful color image is formed in the receiving layer 12. Formed. Then, no paper pattern impression of the transfer paper is generated on the upper surface of the receiving layer 12 on which the color image is formed, and a beautiful color image in which no dot-like mark appears in the receiving layer 12 is obtained.
[0021]
Here, the thickness of the film sheet 15 has a great influence on the quality of the transferred color image, and as a result of various experiments, a thickness of 25 to 50 μm was found to be a preferable thickness range. If the thickness is less than 25 μm, the uneven paper pattern of the transfer paper reaches the receiving layer 12 and moves to the receiving layer. On the other hand, when the thickness is larger than 50 μm, the dye remains in the film sheet 15, and there is a problem that the color tone of the color image formed on the receiving layer 12 is not clear.
[0022]
Further, since the upper surface 12a of the receiving layer 12 is finished to be a smooth surface by polishing, the transfer is performed with a constant applied pressure at any location, so that unevenness in the transfer color tone does not occur. Further, since the smooth upper surface 12a of the receiving layer 12 is in contact with the smooth film sheet 15, the smooth surface is maintained even after pressurization and a clean surface is maintained.
[0023]
Further, since this transfer method is a method of transferring to the film sheet 15 and further transferring from the film sheet 15 to the receiving layer 12, the mixing of the dye becomes good, and dot-like traces that have conventionally occurred We were able to suppress the occurrence of
[0024]
In the above-described embodiment, the display plate using the metal plate as the transfer object has been described. However, the present invention can be applied to other parts that do not use the metal plate, for example, plastic molded parts. A color image can be transferred directly to the molding surface using the transfer method.
[0025]
【The invention's effect】
As described above in detail, according to the present invention, a transparent and smooth film sheet is transferred between the receiving layer and the transfer paper, and the thickness of the film sheet is in the range of 25 to 50 μm. It was possible to transfer a beautiful color image in which the paper pattern of the transfer paper did not move to the receiving layer and no dot-like marks were generated.
[0026]
In addition, according to the present invention, since the transfer is performed after the upper surface of the receiving layer is polished and finished to be a smooth surface, it is possible to transfer a color image without unevenness.
[0027]
Furthermore, according to the present invention, it is possible to eliminate the surface polishing work for removing the paper pattern traces of the transfer paper and the reheating work for erasing the dot-like traces, which were necessary in the conventional transfer method. The cost can be reduced.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing a transfer method according to an embodiment of the present invention.
FIG. 2 is an explanatory view showing a conventional transfer method.
FIG. 3 is a display panel on which a color image is formed with a sublimation dye in a conventional transfer method.
[Explanation of symbols]
10 Display board 12 Receiving layer 15 Film sheet 112 Transfer paper t Width

Claims (4)

In a method of transferring a color image of a transfer paper formed with a sublimation dye ink to a transfer object under heating and pressure,
A color image transfer method comprising transferring a transparent film sheet sandwiched between the transfer paper and a receiving layer formed on the transfer object. 2. The color image transfer method according to claim 1, wherein the transparent film sheet has a thickness of 25 to 50 [mu] m. The transparent film sheet is a film sheet formed of one or more resins selected from polypropylene resin, polyethylene resin, polycarbonate resin, nitrocellulose resin, nitrofuron resin and acrylic resin. The color image transfer method according to claim 1 or 2. 2. The color image transfer method according to claim 1, wherein the surface of the receiving layer is polished to be a smooth surface.

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